package com.wy.test.authentication.core.web;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.security.core.Authentication;
import org.springframework.security.web.access.ExceptionTranslationFilter;
import org.springframework.security.web.authentication.SimpleUrlAuthenticationSuccessHandler;
import org.springframework.security.web.savedrequest.DefaultSavedRequest;
import org.springframework.security.web.savedrequest.HttpSessionRequestCache;
import org.springframework.security.web.savedrequest.RequestCache;
import org.springframework.security.web.savedrequest.SavedRequest;
import org.springframework.util.StringUtils;

import com.wy.test.core.constant.ConstAuthWeb;
import com.wy.test.core.web.AuthWebContext;

/**
 * An authentication success strategy which can make use of the {@link DefaultSavedRequest} which may have been stored
 * in the session by the {@link ExceptionTranslationFilter}. When such a request is intercepted and requires
 * authentication, the request data is stored to record the original destination before the authentication process
 * commenced, and to allow the request to be reconstructed when a redirect to the same URL occurs. This class is
 * responsible for performing the redirect to the original URL if appropriate.
 * <p>
 * Following a successful authentication, it decides on the redirect destination, based on the following scenarios:
 * <ul>
 * <li>If the {@code alwaysUseDefaultTargetUrl} property is set to true, the {@code defaultTargetUrl} will be used for
 * the destination. Any {@code DefaultSavedRequest} stored in the session will be removed.</li>
 * <li>If the {@code targetUrlParameter} has been set on the request, the value will be used as the destination. Any
 * {@code DefaultSavedRequest} will again be removed.</li>
 * <li>If a {@link SavedRequest} is found in the {@code RequestCache} (as set by the {@link ExceptionTranslationFilter}
 * to record the original destination before the authentication process commenced), a redirect will be performed to the
 * Url of that original destination. The {@code SavedRequest} object will remain cached and be picked up when the
 * redirected request is received (See {@link org.springframework.security.web.savedrequest.SavedRequestAwareWrapper
 * SavedRequestAwareWrapper}).</li>
 * <li>If no {@code SavedRequest} is found, it will delegate to the base class.</li>
 * </ul>
 *
 * @author Luke Taylor
 * @since 3.0
 */
public class SavedRequestAwareAuthenticationSuccessHandler extends SimpleUrlAuthenticationSuccessHandler {

	private RequestCache requestCache = new HttpSessionRequestCache();

	@Override
	public void onAuthenticationSuccess(HttpServletRequest request, HttpServletResponse response,
			Authentication authentication) throws ServletException, IOException {
		SavedRequest savedRequest = requestCache.getRequest(request, response);

		if (savedRequest == null) {
			super.onAuthenticationSuccess(request, response, authentication);

			return;
		}
		String targetUrlParameter = getTargetUrlParameter();
		if (isAlwaysUseDefaultTargetUrl()
				|| (targetUrlParameter != null && StringUtils.hasText(request.getParameter(targetUrlParameter)))) {
			requestCache.removeRequest(request, response);
			super.onAuthenticationSuccess(request, response, authentication);

			return;
		}

		clearAuthenticationAttributes(request);

		// Use the DefaultSavedRequest URL
		String targetUrl = savedRequest.getRedirectUrl();

		// is cas login , with service parameter
		logger.trace("CAS " + request.getParameter(ConstAuthWeb.CAS_SERVICE_PARAMETER));
		if (request.getParameter(ConstAuthWeb.CAS_SERVICE_PARAMETER) != null
				&& request.getParameter(ConstAuthWeb.CAS_SERVICE_PARAMETER).startsWith("http")) {
			targetUrl = AuthWebContext.getContextPath(true) + "/authz/cas/login?service="
					+ request.getParameter(ConstAuthWeb.CAS_SERVICE_PARAMETER);
		}
		targetUrl = targetUrl == null ? "/forwardindex" : targetUrl;
		logger.debug("Redirecting to DefaultSavedRequest Url: " + targetUrl);
		getRedirectStrategy().sendRedirect(request, response, targetUrl);
	}

	public void setRequestCache(RequestCache requestCache) {
		this.requestCache = requestCache;
	}
}